Knowledge

Last Updated: Monday, 12th February 2024

From Dribble to Deluge: How To Boost Gravity Fed Systems

If you're dealing with a gravity-fed system and you're not satisfied with the water pressure, you're in the right place. In this comprehensive guide, we'll explore how a hot water pump for a gravity-fed system can be a game-changer for your home.

Can You Fit a Pump to a Gravity Fed System?

Absolutely, you can! Gravity-fed systems are in fact the prime candidates for shower pumps. These pumps can significantly boost your water pressure, turning your shower from a dribble to a deluge. So, if you're tired of low water pressure, fitting a pump to your gravity-fed system is a really viable solution.

Diagram showing how a gravity fed water system works inside the home
Traditional gravity systems served a purpose back in the day, but now are synonymous with low water pressure

Gravity-fed systems are very common in the old housing stock of the UK. Before the time of shower pumps and high pressure showers, we used to rely on gravity to boost our water pressure for us. Now, we want more taps, better showers and these systems are not built for that kind of demand.

How To Increase Water Pressure on Gravity Fed System?

In order to increase the water pressure on a gravity fed system, you'll likely need a shower pump. There are a few factors to consider when choosing your shower pump:

  1. Your flow rate
    You should measure your current flow rate before you get started, as this will help you answer the next point. Learn how to measure your flow rate here.

  2. Are you in Positive or Negative Head?
    Understanding if you are in Positive or Negative head is one of the more important aspects. We'll discuss this in more detail shortly, but essentially if your flow rate is worse than 2 litres/minute, you're in negative head.

  3. Are you boosting just the hot feed, or also the cold feed?
    Is your water pressure poor on both the hot and cold feeds? If so, you'll need a twin impeller pump. If it is just the hot (perhaps your cold water is on the mains) you may be able to get away with a single impeller pump. Learn more about single or double impeller pumps here.

Are You In Positive or Negative Head?

For a gravity-fed system, you have two main options: Positive Head Shower Pumps or Negative Head Shower Pumps. Consider the following diagram. Is your shower in Positive or Negative Head?

Diagram describing when a tap, shower or toilet is in positive or negative head inside a home.
You are in negative head if your appliances are above the line of zero head
Learn more about positive and negative head here

Positive Head Pumps

Positive head shower pumps are recommended when your outlet is in positive head, or if your flow rate is better than 2 litres/minute.

Universal, aka, Negative Head Pumps

Negative head shower pumps can be used in all applications, but they are designed to be used if your flow rate is worse than 2 litres/minute.

How Do You Increase Hot Water Pressure on a Gravity Fed System?

The first thing you need to decide is if you are boosting both the hot and cold feed, or just the hot feed.

Hot Water Boosting Only

If you have good cold water pressure, you may wish to only boost your hot water feed. In this case, you'll need a single impeller shower pump installed close to the hot water tank, like in the diagram above.

Hot Water and Cold Water Boosting

Diagram showing how a twin impeller shower pump may work inside your home

If you have poor water pressure on the hot and cold feeds, you will be wanting to boost both the hot and cold water. In this case, you'll need a twin impeller shower pump installed like in the diagram above.

Check Out Our Shower Pump Buying Guide

If anything's unclear or you have more questions, our in-depth guide to shower pumps is just a click away. Of course, you can always contact us directly for personalised assistance. We're happy to help!

Check out our Shower Pump Buying Guide

Frequently asked questions

Can you fit a pump to a gravity-fed system?

Absolutely, you can! Gravity-fed systems are prime candidates for shower pumps. These pumps can significantly boost your water pressure, turning your shower from a dribble to a deluge.

How do you increase water pressure on a gravity-fed system?

To increase water pressure on a gravity-fed system, you'll likely need a shower pump. Factors to consider include your flow rate, whether you are in Positive or Negative Head, and if you are boosting just the hot feed or also the cold feed.

How do you increase hot water pressure on a gravity-fed system?

To increase hot water pressure, you may wish to only boost your hot water feed. In this case, you'll need a single impeller shower pump, typically installed close to the hot water tank.

Any more questions?

If you have any queries or questions about the products we sell, or even your next project, give us a shout! We'll try our best to give you a hand.